News of the Week m e n t / ' with speakers F. Henry Habicht II of the Environmental Protection Agency and Bruce N. Ames of the University of California, Berkeley (see page 6). In addition, the theme was addressed at several divisional symposia and in a workshop for young science reporters, conducted by the ACS Department of Public Communications. Another special event at the meeting was a "political rally" party, organized by National Chemistry Week staffers, at which several local sections were presented Phoenix Awards for carrying out noteworthy projects during last year's National Chemistry Week. As at other national meetings, various governance committees and the ACS Board and Council discussed a large number of society business matters, including the lawsuit filed against ACS by Dialog In-
formation Services (see page 4) and possible restrictions that may need to be imposed on next year's ACS budget by a declining U.S. economy. Among specific actions taken by the board was completion of the financial commitment to the Smithsonian Institution for the ACS-sponsored exhibit "Science in American Life," bringing total ACS funding to $5.5 million. And the council, among many other matters, adopted both petitions presented to it for amending the society's bylaws. If confirmed later by the board, one will slightly revise the requirements for retired membership status, and the other will reorganize three bylaws on membership requirements, privileges, and dues by gathering into the appropriate bylaw many related clauses scattered throughout the three bylaws. Ernest Carpenter
FROM WASHINGTON
Progress on CFC substitutes discussed Progress was reported last week on several fronts in the effort to phase out ozone-destroying chlorofluorocarbons (CFCs) from the global economy and replace them with environmentally safer alternatives. Toxicity test results on potential CFC substitutes and new strategies for designing halocarbon replacements were discussed at the ACS meeting during a symposium sponsored by the Division of Fluorine Chemistry.
Fifteen CFC producers from nine countries are participating in a program to evaluate the toxicology of several hydrogen-containing halocarbons that could begin replacing CFCs in the near future. The program's toxicology chairman, George M. Rusch of Allied-Signal, reported that so far researchers have seen little or no toxicity associated with HFC-134a (CH2FCF3), HCFC-123 (CHC12CF3), HCFC-141b (CH3CC12F), and HCFC-124 (CHC1FCF3). Testing is continuing, especially long-term exposure studies, and final results will Chlorofluorocarbon alternatives be coming out during the contain hydrogen next few years. H F C - 1 3 4 a is b e i n g Chlorofluorocarbons Alternatives groomed as a replacement CFC-11 (CCI3F) HCFC-123 (CHCI2CF3) for CFC-12 (CC12F2), which HCFC-141b (CH3CCI2F) is widely used in refrigerators and car air conditionCFC-12 (CCI2F2) HFC-134a (CH2FCF3) ers. H o w e v e r , making CFC-113 (CCI2FCCIF2) HCFC-225ca such a substitution will en(CF3CF2CHCI2) tail making trade-offs, HCFC-225cb such as in efficiency, and (CHCIFCF2CCIF2) require changes in lubriCFC-114(CCIF 2 CCIF 2 ) HCFC-124 (CHCIFCF3) cants and expensive redeCFC-115 (CCIF2CF3) HFC-125 (CHF2CF3) sign of equipment. A better alternative yet,
8
September 3, 1990 C&EN
says chemical engineer Donald B. Bivens, is a blend of three fluorocarbons that his company, Du Pont, patented last year (C&EN, Feb. 6, 1989, page 6). The blend, consisting of HCFC-22 (CHC1F2), HFC-152a (CH3CHF2), and HCFC-124, "solves many of the problems we have with HFC-134a," Bivens said at an ACS press conference. The blend has a better energy efficiency than either HFC-134a or CFC-12, he noted. And, he added, "It's been estimated that if in home refrigerators we switched to this new refrigerant, it would save—in the U.S.—the equivalent of one power plant." The HCFC compounds, though, are only temporary alternatives. Because they contain chlorine, they too can deplete stratospheric ozone, although to a lesser extent than CFCs. For this reason, HCFCs are likely to be phased out early in the next century, industry sources say. Looking beyond the horizon, some scientists are seeking unconventional "second-generation" CFC alternatives. For example, fluorine chemist James L. Adcock of the University of Tennessee, Knoxville, is assessing fluorinated ethers and polyethers as potential candidates. In preliminary experiments, his group has synthesized and is studying the thermophysical properties of perfluorinated oxetane (cycZo-CF2CF 2 CF 2 0), perfluorinated dimethoxymethane (CF3-0-CF2-0-CF3), and CF3-0-CF2CF2H. Because their properties are intermediate between those of CFC-11 (CC13F) and CFC-12, they "could function as working fluids in heating /cooling cycles," Adcock says. And because the ethers contain no chlorine, they would be expected to be "kind to the ozone layer." Because of certain structural features, Adcock says, these otherwise stable ethers would be expected to decompose readily in the atmosphere, and thus lead to minimal, if any, greenhouse warming. Their photochemistry hasn't yet been studied in detail, he adds, so no one knows their atmospheric lifetimes. The toxicology of these new CFC alternatives also remains unexplored, although Adcock says they wouldn't be expected to be toxic. Ron Dagani CIRCLE 4 ON READER SERVICE CARD — •
